A system manages device diagnosis and repair workflows using a mobile application and a server-based repair application. The mobile application captures images of a device, computes objective image-quality values including focus or illumination scores, rejects images failing a threshold, and extracts feature descriptors from accepted images for transmission without sending the images. The server-based repair application compares descriptors to stored fault signatures to produce confidence-ranked fault classifications and, when confidence is below a threshold, requests additional captures from predetermined viewpoints using region-of-interest templates until confidence is satisfied or a capture limit is reached. Repair progression is enforced by a server-side state machine that permits only validated state transitions, while clients display only validated states. Replacement workflows may be initiated for non-repairable devices.